Weft thread cutting device for use in shuttleless looms



March 1968 TOEMON SAKAMOTO 3,

WEF'T THREAD CUTTING DEVICE FOR USE IN SHUTTLELESS LOOMS Filed May 18, 1966 United States Patent 3,372,711 WEFT THREAD CUTTING DEVICE FOR USE IN SHUTTLELESS LOOMS Toemon Sakamoto, 299 Hirosawa-cho, Shizuoka-lren, Hamamatsu-shi, Japan Filed May 18, 1966, Ser. No. 551,107 Claims priority, application Japan, Aug. 4, 1965,

3 Claims. (Cl. 139-122) ABSTRACT OF THE DISCLOSURE The invention relates to an electrically heated weft thread cutting device having a first sharp edge for sharply severing a rearmost end of a weft thread from a succeeding length of thread, and a second curved edge for producing a spherical configuration on the forward end of the weft thread.

This invention relates to a weft thread cutting device for use in shuttleless looms, which employs an electric resistance wire as a cutter.

In shuttleless looms, each predetermined length of Weft thread that has been inserted into the shed has to be cut off from the succeeding portion of the thread, and in order to make the salvages of the woven cloth as less bulky as possible, the ends of the weft thread must be cut as sharply as possible. However, in shuttleless looms of the type in which the weft thread is carried through the shed by a jet stream of liquid such as water, it is desirable that the weft thread is cut in such a manner that the succeeding portion thereof has at its forward end a formation spherical or otherwise, so that the jet stream of water can carry the thread more steadily, that is, without tottering on its way through the shed, and at a higher speed.

Accordingly, the primary object of the invention is to provide a weft thread cutting device which is capable of cutting the weft thread so that the rear end of each predetermined length of weft thread that has just been inserted into the shed is sharply cut from the succeeding portion of the thread, with a generally spherical formation simultaneously produced on the forward end of the succeeding portion of the thread. To accomplish the object, the device of the invention includes electric resistance wire means arranged at one side of the loom for relative movement transverse of the axis of the weft thread. The resistance wire means functions as a cutter when heated upon flow of electric current therethrough, and comprises a first and a second generally linear portion arranged side byside with the first portion positioned nearer to the loom side. The first portion of the cutting wire has such a sharp longitudinal edge on its side toward the weft thread as to effect a substantial point contact therewith, while the second portion of the cutting wire has a surface which is flat, or slightly convexly curved or otherwise, on its side toward the weft thread so as to effect a contact therewith at a larger area, Upon transverse movement of the cutting wire relative to the weft thread that has been inserted into the shed, the end adjacent the selvage is contacted by the sharp edge of the first portion of the heated cutting wire and thereby sharply cut off from the succeeding portion of the thread, the forward end of which is simultaneously contacted by the side surface of the second portion of the cutting wire which melts the substance of that portion of the thread so that a generally spherical formation is produced thereon.

The above and other objects, features and advantages of the invention will become apparent from the following detailed description thereof with reference to the accompanying drawings, wherein:

FIG. 1 is a side elevational View, partly in section, of one embodiment of the invention, with its related parts of a shuttleless loom;

FIG. 2 is a view taken on the line AA of FIG. 1;

FIG. 3a is an enlarged, transverse sectional View of the cutting wire, schematically showing the manner in which the weft thread is cut by the two differently shaped portions of the cutting wire;

FIG. 3b is a view similar to FIG. 3a but showing a modified form of the cutting wire; and

FIGS. 4 to 6 are schematic drawings showing the different steps of the cutting operation.

Now referring in detail to the drawings, there is shown in FIGS. 1 and 2 a lay beam 10 carrying reed 11 thereon and mounted on the swords 12 suitably mounted on a shaft 13 journaled on the frame of the loom (not shown) for rocking movement thereon. A jet projector 14 mounted on the machine frame is directed toward the shed at one side thereof and connected through a pipe 15 to a source of pressurized liquid. Every time the shed is opened, the projector jets a stream of pressurized liquid, which carries the weft thread through the open shed, and the thread lying in the shed is then beaten by the reeds into the cloth, as is well known in the art.

The lay beam 10 is provided with a bracket 16 secured to one side surface thereof, to which a lever 17 is pivoted by a pin 18. The lever 17 extends substantially in parallel with the reeds and has a vertically spaced pair of fingers or arms 17 between which is supported a cutter comprising an electric resistance wire 19 wound in a single turn and connected by leads 20, 20 to a suitable source of electricity, not shown. A spring 21 wound around the pin 18 has its free end engaged with the lever 17 to urge the same and consequently hold the cutting wire 19 away from the plane of the reed 11. The wire 19 is held at that position by an adjustable stopper 22 threadedly mounted on the lever 17 and having one end abutting on a tongue 23 depending from the lay beam 10. A bracket 24 is secured to the frame by a bolt 25 and provided with a bolt 26 having one end adjustably screwed to the bracket and the opposite free end projecting toward the lower end of the lever 17. As the swords 12 are moved counterclockwise in FIG. 1 to beat the inserted weft thread into the cloth, the outer end of the bolt 26 comes to hit on the lower end portion of the lever immediately before the extreme end of the rocking movement of the swords, thereby moving the lever 17 counterclockwise on the pin 18 against the force of the spring 21 so that the cutting wire moves beyond the plane of the reed, as shown in dash-and-dot lines in FIG. 1, to cut ofi the rear end of the inserted weft thread as will be described hereinafter.

The operation of the loom will now be described with reference to FIGS. 4 to 6. When the shed is opened, a predetermined length of weft thread 27 is projected by a stream of liquid jetted from the projector 14 through the shed to lie therein anterior of the reed, with the lay beam 10 being at this time held substantially in its backmost position (FIG. 4). As the lay beam ltll moves forward, the reed moves the inserted weft thread towards the fell of cloth 28. As the weft thread is thus moved, it is straightened up by the reed. Meanwhile, the cutting wire 19 is held posterior of the plane of the reed although it moves together with the reed (FIG. 5). When the lay beam has reached a position immediately before its foremost posi tion, the lower portion of the lever 17 is hit on by the outer free end of the bolt 26, so that the lever is turned counterclockwise in FIG. 1 for the cutting wire 19 to move faster than the lay beam or reed until it cuts the 3 plane of the reed, during which course the heated wire contacts the weft thread to melt and cut the same (FIG. 6).

The characteristic of the invention lies in that the cutting wire has two different portions arranged side by side at one side of the loom, and that one of the portions on the loom side is so formed as to enable a substantial point contact between the portion of the Cutting wire and the weft thread, while the other portion thereof arranged on the projector side is so formed as to effect a contact between the portion and the thread at a larger area. In the embodiment of FIG. 3a, the cutting wire 19 is so wound in a single turn between the two arms of the lever as to form two generally linearly extending portions a and b. As most clearly shown in FIG. 3a, the portion a on the 100m side is V-shaped in transverse section so that it has a longitudinal sharp edge on its side toward the weft thread, while the portion b on the projector side is elliptical in transverse section so that it has a surface, generally fiat or slightly convexly curved, on its side toward the weft thread. In FIG. 3b, the cutting wire 19 comprises a pair of separate, independent wires a and b which are wound on the two arms of the lever to present traverse sections similar to the portions a and b, respectively. It will be easily seen that upon contact of these two portions with the weft thread, the sharp edge of the portion a, a, sharply cuts the rear end of a predetermined length of Weft thread that has been inserted through the shed, while the flat surface of the portion b, b melts a greater portion of the weft thread, with a resulting generally spherical formation 29 produced on the forward end of the portion of the weft thread that has been separated from the inserted portion of the thread and that is next to be inserted into the shed. The spherical formation 29 makes it easier for the liquid to carry the weft thread more steadily and at a higher speed in the next weft thread inserting operation. The weft thread that has thus been inserted into the shed then has its forward end portion with the spherical formation cut off by a suitable cutter provided at the opposite side of the loom and its rear end sharply cut in the above mentioned manner, so that nothing bulky is left at the opposite sides of the cloth.

Having illustrated and described preferred embodiments of the invention, it should be noted that there are many changes and modifications thereof without departing the true scope and spirit of the invention as defined in the appended claims.

What I claim is:

1. A weft thread cutting device for use in shuttleless looms of the type wherein the weft thread is carried into a warp shed by a stream of pressurized liquid, comprising an electric resistance wire means; means for carrying electric current to said electric resistance wire means to heat the same; means for supporting said electric resistance wire means at one side of the loom; and means for moving said supporting means so that said electric resistance wire means is moved transversely of the axis of the inserted weft thread; wherein said resistance wire means comprises a single length of resistance wire so wound in a single turn as to form a first and a second generally linearly extending portion arranged side by side with said first portion positioned nearer to the loom side, said first portion having such a sharp edge on its side toward the weft thread as to effect a substantial point contact with the weft thread, whereby at said one side of the loom the weft thread is contacted and severed by said resistance wire means, while said second portion has such a surface on its side toward the weft thread as to effect a contact therewith at a relatively large area.

2. The device as defined in claim 1, wherein said supporting means comprises a lever pivoted between its opposite ends to one side of the loom lay beam for simultaneous rocking movement therewith, said resistance wire means being secured to one end portion of said lever, said lever being normally so positioned that said resistance wire means is normally held away from the plane of the reed carried on the lay beam; and said moving means comprises a rod having one end rigidly secured to the loom frame with its opposite free end projecting toward the opposite end portion of said lever so that during the course of the rocking movement of said lay beam in the weft thread beating direction, the free end of said rod hits on said opposite end portion of said lever to thereby cause said one end portion of said lever to traverse the plane of said reed.

3. A weft thread cutting device for use in shuttleless looms of the type wherein the weft thread is carried into a warp shed by a stream of pressurized liquid, comprising an electric resistance wire means; means for carrying electric current to said electric resistance wire means; means for supporting said electric resistance wire means at one side of the loom; and means for moving said supporting means so that said electric resistance wire means is moved transversely of the axis of the inserted weft thread; where in said resistance wire means comprises a pair of separate resistance wires extending side by side, one of said resist ance wires positioned near the loom side and having such a sharp longitudinal edge toward the weft thread as to effect a substantial point contact with the weft thread, whereby at said loom side the weft thread is contacted and severed, while the other of said resistance wires has such a surface on its side toward the weft thread as to effect a contact therewith at a relatively large area.

References Cited UNITED STATES PATENTS HENRY S. JAUDON, Primary Examiner. 

